1. Field of the Invention
The present invention relates to a recording apparatus which can operate by using a fuel cell as a power source.
2. Description of the Related Art
Fuel cells directly obtain an electric energy from a chemical energy by electrochemically reacting a fuel such as hydrogen or methanol with oxygen. Accordingly, there is an expectation that, as power sources having high power generation efficiency, the fuel cells have a wide range of applications to power sources for portable devices, distributed power sources for electric vehicles, institutional use, or domestic use, or the like.
In the fuel cells, since an energy density of hydrogen itself is high and an active substance on a cathode side is not necessary because oxygen is taken in from the external air, an energy capacity per volume and per weight can be dramatically increased compared to a conventional battery.
Of those fuel cells, a polymer electrolyte fuel cell employing a polymer electrolyte membrane having proton conductivity can be operated at about room temperature, and is particularly suitable for downsizing.
Conventionally, in Japanese Patent Application Laid-Open No. 2005-262592, there is a suggestion to use the polymer electrolyte fuel cell of this type as a power source for a printer (recording apparatus).
When the printer is operated by the fuel cell, even in an environment such as outdoors, in which ac power cannot be received from a commercial outlet, a printing processing can be performed.
However, the printer according to Japanese Patent Application Laid-Open No. 2005-262592 as the conventional example has the following problems.
That is, an amount of fuel used by the fuel cell changes depending on operating conditions of the printer, so timings at which the ink and the fuel are exhausted generally differ from each other.
Therefore, for example, when the fuel is exhausted during printing, power generation by the fuel cell cannot be performed at this time point, so there arises a problem of printer stop.
Further, for example, in a case where an ink cartridge and a fuel tank are used while being integrated into a single body, when one of the ink and the fuel is exhausted to be replenished with a new ink or fuel is to be performed, there arises a problem in that one of the fuel and the ink, which still remains, is inevitably discarded.
A further description thereof is made as follows. That is, the polymer electrolyte fuel cell performs the power generation by using hydrogen or methanol as the fuel and by reacting the hydrogen or methanol with oxygen in air. In order to realize this, the fuel has to be supplied.
In a case where the printer is operated by the fuel cell, when the fuel is exhausted during printing, the power generation by the fuel cell cannot be performed at this time point, and there arises a problem in that the printer is stopped and a printing operation is interrupted.
Further, for example, in the case where the ink cartridge and the fuel tank are used while being integrated into the single body, when the fuel which has been exhausted during printing is replenished the expensive ink is discarded, thereby causing an increase in running costs of the printer.
On the other hand, the fuel is normally less expensive than the ink. However, when a sufficient amount of the fuel is stored so that the ink is exhausted earlier than the fuel, the fuel has to be discarded when replacing the cartridge.
The discarding of the fuel consumes time and effort and involves high costs, thereby being extremely inconvenient.
Further, in a case of using methanol as the fuel, there is a need of taking a countermeasure for toxicity, so extra costs are further required.